1. Field of the Invention
The present invention relates to a fastener. The fastener has particular utility in securing a sheet of flexible material in a desired position, securing one such sheet to another, or securing a desired object to such a sheet.
2. Description of Related Information
It is frequently desirable to securely hold a sheet of plastic, canvas, waterproof tarpaulin, fabric, or other material in a particular location. For example, fastening means are desirable for securing a tent to its stakes.
It is also desirable on occasion to secure two or more sheets to each other or to secure an object to a sheet, such as a lamp hanging within a tent, or a weight hanging from the side of a sheet. In certain applications, it is also desirable to prevent rotation of a sheet of material relative to a fastener or stationary object since rotation may initiate stretching or tearing of the sheet, and may disturb items covered by the sheet.
In the past, a variety of devices were used for fastening sheets to other objects, including devices that employed collar-retainer systems. In a collar-retainer system, the retainer may be alternately engaged or disengaged within the collar. By placing the sheet between the collar and retainer before engaging the two, the collar-retainer system is secured to the sheet. Two sheets may be attached to one another by placing both within a collar-retainer. To secure the sheet to another object, collar-retainer systems have employed hooks or slots integrally attached to the collar.
In a collar-retainer system, there must be sufficient clearance or flexibility between the retainer and collar to allow one or more sheets to be placed therebetween. However, the retainer and collar must also form a tight enough connection to prevent the retainer and collar from disengaging under stress. Devices employed in the past suffered from collar-retainer combinations that were too tight, resulting in difficulty of use and an increased risk of contact part fatigue, or too loose, resulting in a lack of dependability due to collar-retainer separation under stress.
In addition, fasteners in the past featured circular retainer-collar combinations that allowed relative rotation. Those retainer-collar systems that did not employ circular combinations employed collars having oddly shaped protrusions subject to fatigue failure under repeated stress. Finally, fasteners in the past used hooks or slots that suffered from limited versatility due to their size--and means--specific nature, and due to inaccessible connection points.
A need exists, therefore, for a fastener that provides a tight fit between the retainer and the collar but allows placement of a sheet therebetween, that is quick and easy to engage and disengage, and that is relatively free of easily fatigued protrusions. A need also exists for a fastener that is versatile enough to be securely attached to hooks, ropes, screws, nails, conventional tent stakes, and a variety of other securing means. Finally, a need exists for a fastener that can be secured in a given orientation and that will resist rotation therefrom.